Improvement in steam-engine slide-valves



@eine tate stmt fits.

E. J. PIP-ER AND J. C. MARSHALL, 0F SPRINGFIELD, MASSACHUSETTS. Letters Paten-t .Na 68,312, dated August 27, 1867 amfdatecl August 15, 1867.

IMPROVEMENT IN STEAM-ENGINE SLIDE-VALVES.

@In ndgrhule referat in in tlgese Vttas ntent mth, mating .part nf tige arme.

TO ALL WHOM. IT MAY CONOERN:

`Be it known that we, E. J. PIPER and J. C.:BfIARsI-IALL, of Springfield, Hampden county, Commonwealth of Massachusetts, have invente'da new and useful Improvement in Slide-Valves for Steam Enginesf and we do hereby declare that the following is a. full and exact description thereof, reference being had to the accompanying drawings,- and `lio-the letters'bf reference marked thereon. These drawings are- Figure 1 a side, and

Figure 2 a plan View of ,a steam cylinder, with our improved slide-valve attached,

Our invention consists of the arrangement of an adjustable gib upon the top of the valve, in the manner and for the purpose hereafter described.

In ordinary` slide-valves, steam is let on in such a manner as to press upon the top of the valve, thus causing alarge amount of friction upon the valve and seat, and thus causingboth to wear. Various complicated modes of relieving this pressure, by forming a balance-valve, have heretofore been devised, and it's the object of this invention to accomplish this purposein un extremely simple and compact manner. l i

We formthe valve in the ordinary manner, as shown, and on the top of it place the gib A, which fits up against the `valvechest and is adjusted by means of the set-screws a a a. By this means steam is prevented from getting upon the top of the valve and pressing it down upon its seat, and thus the friction-.between the valve and seat is relieved. The set-screws a a a are so arranged that they can be' turned fromthe outsitle'of the chest, thus adjusting the fit of the valve between the sides Without taking the chest apart.

Now, having described our invention, what we claimas nevv, and desire to secure by Letters Patentis- In combination with the valve B, the gib A, arranged substantially as described, and adjustable from the outside of the valve-chest, as herein set forth.

E. J. PIPER,

J. C. MARSHALL.

Witnesses: j

J, B. GABDINER, EDWD. H. HYDE, 

